Terrapower, a startup funded in part by Nathan Myhrvold and Bill Gates, is moving closer to building a new type of nuclear reactor called a traveling wave reactor that runs on an abundant form of uranium. The company sees it as a possible alternative to fusion reactors, which are also valued for their potential to produce power from a nearly inexhaustible source of fuel.

Work on Terrapower's reactor design began in 2006. Since then, the company has changed its original design to make the reactor look more like a conventional one. The changes would make the reactor easier to engineer and build. The company has also calculated precise dimensions and performance parameters for the reactor. Terrapower expects to begin construction of a 500-megawatt demonstration plant in 2016 and start it up in 2020. It's working with a consortium of national labs, universities, and corporations to overcome the primary technical challenge of the new reactor: developing new materials that can withstand use in the reactor core for decades at a time. It has yet to secure a site for an experimental plant—or the funding to build it.

The reactor is designed to be safer than conventional nuclear reactors because it doesn't require electricity to run cooling systems to prevent a meltdown. But the new reactor doesn't solve what is probably the biggest problem facing nuclear power today: the high cost of building them. John Gilleland, Terrapower's CEO, says the company expects the reactors to cost about as much to build as conventional ones, "but the jury is still not in on that."

Conventional reactors generate heat and electricity as a result of the fission of a rare form of uranium—uranium 235. In a traveling wave reactor, a small amount of uranium 235 is used to start up the reactor. The neutrons the reactor produces then convert the far more abundant uranium 238 into plutonium 239, a fissile material that can generate the heat needed for nuclear power. Uranium 238 is readily available in part because it's a waste product of the enrichment processes used to make conventional nuclear fuel. It may also be affordable in the future to extract uranium 238 from seawater if demand for nuclear fuel is high. Terrapower says there's enough of this fuel to supply the world with power for a million years, even if everyone were to use as much power as people in the United States do.,

Very interesting, and broadly cause for celebration! My only question: The neutrons the reactor produces then convert the far more abundant uranium 238 into plutonium 239, a fissile material that can generate the heat needed for nuclear power. Who will generate using plutonium? it carries a considerable risk premium.

But the new reactor doesn't solve what is probably the biggest problem facing nuclear power today: the high cost of building them. John Gilleland, Terrapower's CEO, says the company expects the reactors to cost about as much to build as conventional ones, "but the jury is still not in on that."

What about the high cost of cooling the waste for thousands of years, so it won't blow up?

But the new reactor doesn't solve what is probably the biggest problem facing nuclear power today: the high cost of building them. John Gilleland, Terrapower's CEO, says the company expects the reactors to cost about as much to build as conventional ones, "but the jury is still not in on that."

What about the high cost of cooling the waste for thousands of years, so it won't blow up?

In the aftermath of the disaster in Japan, this is what Terrapower said:

“Comparing our design with the reactors at the center of the crisis in Japan is like comparing a Ford Model T with a Volvo S80. It’s important to remember Japan’s troubled reactors were designed in the 1960′s. However, even though the earthquake and tsunami exceeded their design basis, the reactors remain essentially intact,” Intellectual Ventures wrote.

The firm also noted two key points of TerraPower’s design—it doesn’t have holding pools for spent fuel and doesn’t use the “light water” technology employed at the troubled plant in Japan.

“These two features alone would avoid the major problems encountered with light water technology,” Intellectual Ventures reported. It also added: “Safety is our top priority and we remain committed to defining a simple fuel cycle that ensures our plants operate safely no matter the conditions.”

But the new reactor doesn't solve what is probably the biggest problem facing nuclear power today: the high cost of building them. John Gilleland, Terrapower's CEO, says the company expects the reactors to cost about as much to build as conventional ones, "but the jury is still not in on that."

What about the high cost of cooling the waste for thousands of years, so it won't blow up?

In the aftermath of the disaster in Japan, this is what Terrapower said:

“Comparing our design with the reactors at the center of the crisis in Japan is like comparing a Ford Model T with a Volvo S80. It’s important to remember Japan’s troubled reactors were designed in the 1960′s. However, even though the earthquake and tsunami exceeded their design basis, the reactors remain essentially intact,” Intellectual Ventures wrote.

The firm also noted two key points of TerraPower’s design—it doesn’t have holding pools for spent fuel and doesn’t use the “light water” technology employed at the troubled plant in Japan.

“These two features alone would avoid the major problems encountered with light water technology,” Intellectual Ventures reported. It also added: “Safety is our top priority and we remain committed to defining a simple fuel cycle that ensures our plants operate safely no matter the conditions.”

there is plenty of place for the waste, we just stopped using it. There is another post on here that shows all the nuclear explosions in the world and most were in our country by our hands. I don't care if a little waste goes down the rail road tracks.